Why am I seeing the the htmlWebpackPlugin.options.title tag in my Firebase site?

I deployed a Vue.js project to firebase, but when I clicked on the link, the page was blank, and the tab title of my browser is the placeholder:

<%= htmlWebpackPlugin.options.title >

What I did:

? What do you want to use as your public directory? dist
? Configure as a single-page app (rewrite all urls to /index.html)? Yes
? Set up automatic builds and deploys with GitHub? No
? File dist/index.html already exists. Overwrite? No

Checked the console, and got this error: Failed to load resource: the server responded with a status of 400 ()

I cannot get my Vue.js app to work on my browser! How can I fix it?